The present invention provides corrosion resistant glycol compositions.
Compositions containing glycols and various corrosion inhibitors are well known in the prior art as is illustrated by U.S. Pat. Nos. 3,282,846, dated Nov. 1, 1966; 3,362,910, dated Jan. 9, 1968 and 3,340,001, dated Sept. 5, 1967. The use of the relatively inexpensive and effective borax and silicates in formulations is well illustrated by these patents. It is conventional in this art to make an aqueous organic concentrate which is then sold to end users for use as a coolant in internal combustion engines fitted with radiators and other heat exchangers. The concentrate is normally used after dilution with water.
The use of acetylacetone is known as a corrosion inhibitor for aluminum in hydrochloric acid solutions (Desai et al; J. Indian Chem. Soc., Vol 73, Series 50, pages 341-343).
In an investigation of 68 potential corrosion inhibitors for aluminum in glycol-water systems Northan et al. (Proceed. of 24th Conference, Nat'l. Ass'n. of Corrosion Engineers, 1969) (Chem Abstracts 72:5730j) did not suggest the use of .beta.-diketo compounds.
U.S. Pat. No. 3,615,888 dated Oct. 26, 1971 discloses the use of .beta.-diketones to coat bare metals prior to the painting thereof. There is no suggestion in the patent of the compositions of this invention.